Object.assign(obj1, obj2)
Object.is(obj1, obj2)
Object.keys(obj)
Object.defineProperty(obj, "attr", {
    value: '',
    enumerable: false
})
Object.defineProperties(obj, {
    attr1: {

    },
    attr2: {

    }
})
obj1.isPrototypeOf(obj2) // obj1是否存在于obj2的原型链中
